This invention pertains to apparatus for selectively driving a magnetic tape, or the like, in reverse directions. For the purpose of illustration herein, a preferred embodiment, and a modification, of the invention are described in conjunction with a tape deck of the type used in a telephone answering device.
Various types of recording equipment, such as a telephone answering device, utilize a tape deck wherein a length of magnetic recording tape is selectively driven in reverse directions to record, playback and erase various messages. Such equipment is usually placed in use under circumstances where it is unattended, and in this situation, it is, of course, desirable that the equipment exhibit a high degree of performance reliability. Further, equipment, such as telephone answering devices, is beginning to receive relatively wide-spread use, including use in private homes. It is thus further desirable to be able to offer such equipment at a relatively low cost, so that it will be economically available to a large number of users. Hence, it is obviously advantageous to offer a relatively simple and lowcost construction in the mechanism used in the equipment.
A general object of the present invention, therefore, is to provide a unique system, or apparatus, for selectively, reversibly driving a magnetic tape, or the like, which apparatus takes the above considerations into account in a practical and satisfactory manner.
More specifically, an object of the invention is to provide a relatively simple, low-cost, reliable system for reversibly driving such a tape.
According to the invention, what is proposed is a pair of adjacent, but spaced-apart rotary shafts which are driven simultaneously, and in a common direction by a single drive motor. In the embodiments of the invention described below, one of these shafts is the output shaft of the motor itself, and the other is driven by the motor through pulleys and a belt. Provided for each shaft is a pinch roller which is movable into and out of engagement with the shaft for pinching against a stretch of tape extending between it and the shaft. Guide means is also provided for guiding a length of tape between each pinch roller and its associated shaft, with such a length of tape extending on one side of one shaft (considering its direction of rotation) and on the opposite side of the other shaft. The pinch rollers are similarly located on opposite sides of their respective shafts.
The pinch rollers in the apparatus are mounted on carriers which are pivoted on a deck that carries the apparatus, with a biasing spring acting on one of these carriers, and between this carrier and the deck, tending to urge the carriers into disengagable contact with each other. Further provided is a push mechanism for acting on the carriers to shift their positions against the action of this biasing spring.
More specifically, the biasing spring just mentioned normally urges the carriers into positions where one pinch roller engages its associated shaft, with the other pinch roller then being out of engagement with its associated shaft. Operation of the push mechanism reveses this situation. An operative interconnection between the carriers results in movement of one carrier to place its pinch roller against its associated shaft causing simultaneous movement of the other carrier to shift its pinch roller out of engagement with its associated shaft.
As will become apparent from the description which now follows, this construction results in an extremely simple assembly which offers a high degree of reliability. Further, it will become apparent that the proposed construction can be manufactured and assembled at relatively low cost.
These and other features and advantages of the invention will become more fully apparent as the descriptive material below is read in conjunction with the accompanying drawings.